scholarly journals AreDeschampsia caespitosa(L.) Beauv. Tussocks Safe Sites for Seedling Recruitment in the Succession of Wet Meadows?

2014 ◽  
Vol 62 (4) ◽  
pp. 707-721 ◽  
Author(s):  
Kinga Kostrakiewicz-Gierałt
Keyword(s):  
Seedling Recruitment ◽  
Safe Sites ◽  
Wet Meadows

Recruitment and life-history traits of sparse plant species in subalpine grasslands

2003 ◽  
Vol 81 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Gunnar Austrheim ◽  
Ove Eriksson
Keyword(s):  
Leaf Area ◽  
Negative Correlation ◽  
Specific Leaf Area ◽  
Seedling Recruitment ◽  
Plant Traits ◽  
Dry Weight ◽  
Community Diversity ◽  
Safe Sites ◽  
Subalpine Grasslands ◽  
Leaf Dry Weight

Recruitment is critical for the maintenance of plant populations and community diversity, but sexual regeneration is considered to be infrequent in climatically harsh habitats such as subalpine grasslands. This study examines the importance of regeneration through seed for 16 sparse herb species, and we asked whether their populations are limited by safe sites or the availability of seeds. Seedling recruitment and winter survival were recorded after sowing in an experimental split-plot design in (i) pasture grazed by livestock, and (ii) exclosed grassland cultivated for annual mowing. In addition we examined the effect of disturbance and local seedbank recruitment. All species were able to recruit and survive the first winter in at least some of the experimental plots, although none were initially present. Recruitment mainly occurred in disturbed plots, and disturbed pasture plots had a significantly higher recruitment than disturbed exclosures for all species except Silene dioica. We further examined whether specific plant traits were related to variation in recruitment. Lower recruitment in the disturbed exclosure was associated with higher specific leaf area, leaf dry weight, and seed number. In contrast, seeds sown in disturbed pasture recruited more independently of species traits. The exception was a negative correlation between recruitment and leaf dry weight, and an unexpected negative correlation with seed weight. We suggest that recruitment differences among habitats mainly reflect lower humidity in the exclosure. Consequently, small stature plants with small specific leaf area should have the highest recruiting probability when exposed to drought. The almost exclusive recruitment on disturbed plots indicates a strong competitive effect on the target species in vegetated plots, and suggests that safe sites for regeneration through seed are rare in subalpine grasslands.Key words: colonization, herbs, plant abundance and distribution, disturbance, pastures, cultivated exclosures, sowing experiment.

scholarly journals Tree colonization of sub-Mediterranean grasslands: effects of dispersal limitation and shrub facilitation

2007 ◽  
Vol 37 (1) ◽  
pp. 103-115 ◽  
Author(s):  
Georges Kunstler ◽  
Joël Chadœuf ◽  
Etienne K Klein ◽  
Thomas Curt ◽  
Monique Bouchaud ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Seedling Recruitment ◽  
Dispersal Limitation ◽  
Tree Seedling ◽  
Mature Trees ◽  
Quercus Pubescens ◽  
Safe Sites ◽  
Buxus Sempervirens ◽  
Canopy Area ◽  
Dispersal Distances

Encroachment of trees into low-productivity grasslands is a serious threat to grassland biodiversity throughout Europe. Although the rate of encroachment of trees into grassland is variable and poorly understood, it is thought to result from variation in tree seedling recruitment, which is limited mainly by the availability of safe sites and the dispersal distances of propagules. In this study, we established spatially explicit models of seedling recruitment for two major sub-Mediterranean trees: Quercus pubescens Willd. and Fagus sylvatica L. We quantified the spatial distribution of Q. pubescens and F. sylvatica seedlings up to 20 years old at three grassland sites. We also quantified the spatial distribution and size of mature trees and of the two dominant species of shrubs, Buxus sempervirens L. and Juniperus communis L., at each of the three sites. Ninety-eight percent of the regeneration took place under shrub canopy. Quercus pubescens seedlings showed higher seedling production per unit of canopy area and longer mean effective dispersal distances than did F. sylvatica seedlings. Quercus pubescens seedlings also had a large advantage over F. sylvatica seedlings for establishment in open areas. Juniperus shrubs were better safe sites for the establishment of Q. pubescens and F. sylvatica seedlings than were Buxus shrubs. We calculated indices of seedling dispersal limitation and safe site availability for recruitment for four dates. In the dolomitic Causse grasslands examined in this study, the availability of safe sites for germination and survival was far more important than seedling dispersal limitation for recruitment of both tree species.

Plant mortality and seedling recruitment responses to flupropanate in grassland populations of Nassella trichotoma

2017 ◽  
Vol 70 ◽  
pp. 160-164 ◽  
Author(s):  
G.W. Bourdôt ◽  
S. Jackman ◽  
D.J. Saville
Keyword(s):  
New Zealand ◽  
Dose Response ◽  
Sodium Salt ◽  
Seedling Recruitment ◽  
Residual Activity ◽  
Application Rate ◽  
Plant Mortality ◽  
Complete Control ◽  
Bio Synthesis

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.

Meadows of the North-Eastern Altai

2002 ◽  
pp. 22-31 ◽  
Author(s):  
T. V. Maltseva ◽  
N. I. Makunina
Keyword(s):  
Coniferous Forest ◽  
Wet Meadows ◽  
Abies Sibirica ◽  
Dark Coniferous Forest ◽  
Hay Meadows ◽  
The North ◽  
North Eastern ◽  
Humid Area ◽  
River Valleys

The North-Eastern Altai is an ultra-humid area with climax vegetation represented by tall-herb fir (Abies sibirica) dark-coniferous forest. Its meadows belong to the class Molinio-Arrhenatheretea. The typical asso­ciation Aegopodio podagrariae—Dactyletum glomeratae originates in the watershed clearings after climax forests whereas ass. Hyperici perforati—Agrostietum giganteaereplaces the previous one under mowing and grazing. The Molinietalia wet meadows are widespread in the river valleys. The meadows of ass. Cirsio heterophylli—Calama­grostietum langsdorffii occur on wet soils in small depressions and along floodplain mire margins, and ass. Ca­rici ovalis—Deschampsietum cespitosae comprises typical floodplain hay-meadows on moist, nutrient-rich soils.

Large-scale vegetation mapping of the Pinega river valley (the surroundings of Golubino village, Arkhangelsk oblast)

2018 ◽  
pp. 19-39
Author(s):  
M. A. Makarova
Keyword(s):  
Plant Communities ◽  
Indicator Species ◽  
Dominant Species ◽  
Large Scale ◽  
Vegetation Mapping ◽  
River Valley ◽  
Floodplain Forests ◽  
Floodplain Vegetation ◽  
Wet Meadows ◽  
Arkhangelsk Oblast

Geobotanical survey of floodplain natural complexes near gypsum outcrops in the Pinega river valley was done in 2015. Large-scale geobotanical map of the key polygon (scale 1 : 30 000) was composed. Typological units of vegetation were selected on the basis of the composition of dominant species and groups of indicator species. Homogeneous and heterogeneous territorial units of vegetation (serial series, combinations, environmental series) were used. 53 mapped unit types (25 homogeneous types and 28 heterogeneous types) were recognized. The floodplain vegetation consists of 17 homogeneous types of plant communities, 3 series, 14 combinations and 6 ecological series. The sites of old floodplain forests, such as willow forests with Urtica sondenii rare in the Arkhangelsk region and oxbow wet meadows with Scolochloa festucacea were identified.

scholarly journals The influence of two wildfires and biological control agents on the population dynamics of Melaleuca quinquenervia in a seasonally inundated wetland

2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Seedling Recruitment ◽  
Additional Treatment ◽  
Seed Rain ◽  
The Other ◽  
Melaleuca Quinquenervia ◽  
Biological Control Agents ◽  
Seedling Mortality ◽  
Sapling Growth

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.

Unraveling the roles of various ecological factors in seedling recruitment to facilitate plant regeneration

2021 ◽  
Vol 492 ◽  
pp. 119219
Author(s):  
Yuan-Yuan Li ◽  
Yu-Pei Liu ◽  
Jun Gong ◽  
Shen-Hou Fan ◽  
Guo-Chun Shen ◽  
...  
Keyword(s):  
Plant Regeneration ◽  
Seedling Recruitment ◽  
Ecological Factors
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